document.addEventListener('DOMContentLoaded', function() {
    // Initialize local storage for study tracking
    if (!localStorage.getItem('studySessions')) {
        localStorage.setItem('studySessions', '0');
    }
    
    if (!localStorage.getItem('studyStreak')) {
        localStorage.setItem('studyStreak', '0');
    }
    
    if (!localStorage.getItem('lastStudyDate')) {
        localStorage.setItem('lastStudyDate', new Date().toDateString());
    }
    
    // Check if user studied today to update streak
    const lastStudyDate = localStorage.getItem('lastStudyDate');
    const today = new Date().toDateString();
    
    if (lastStudyDate !== today) {
        // Reset streak if more than one day has passed
        const lastDate = new Date(lastStudyDate);
        const todayDate = new Date();
        const diffTime = Math.abs(todayDate - lastDate);
        const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24));
        
        if (diffDays > 1) {
            localStorage.setItem('studyStreak', '0');
        }
    }
    
    // Update UI with stored data
    updateStudyStats();
});

function updateStudyStats() {
    const sessions = localStorage.getItem('studySessions');
    const streak = localStorage.getItem('studyStreak');
    
    document.querySelectorAll('.session-count').forEach(el => {
        el.textContent = sessions;
    });
    
    document.querySelectorAll('.streak-count').forEach(el => {
        el.textContent = streak;
    });
}
function startStudySession(subject) {
    // Validate subject
    if (!subject) {
        showErrorToast("Please select a subject to study!");
        return;
    }

    // In a real app, this would start tracking study time
    console.log(`Starting study session for ${subject}`);
    
    // Update session count
    const sessions = parseInt(localStorage.getItem('studySessions')) + 1;
    localStorage.setItem('studySessions', sessions.toString());
    
    // Update streak if needed
    const lastStudyDate = localStorage.getItem('lastStudyDate');
    const today = new Date().toDateString();
    
    if (lastStudyDate !== today) {
        const streak = parseInt(localStorage.getItem('studyStreak')) + 1;
        localStorage.setItem('studyStreak', streak.toString());
        localStorage.setItem('lastStudyDate', today);
    }
    
    updateStudyStats();
    showSuccessToast(`Started studying ${subject}! Good luck!`);
}
function showErrorToast(message) {
    const toast = document.createElement('div');
    toast.className = 'fixed bottom-4 left-1/2 transform -translate-x-1/2 bg-red-500 text-white px-6 py-3 rounded-lg shadow-xl flex items-center animate-fade-in z-50';
    toast.innerHTML = `
        <div class="flex items-center">
            <i data-feather="alert-circle" class="mr-2"></i>
            <span>${message}</span>
        </div>
        <div class="absolute bottom-0 left-0 h-1 bg-red-300 rounded-b-lg w-full origin-left animate-progress"></div>
    `;
document.body.appendChild(toast);
    feather.replace();
    
    setTimeout(() => {
        toast.classList.add('opacity-0', 'transition-opacity', 'duration-300');
        setTimeout(() => toast.remove(), 300);
    }, 3000);
}
function showSuccessToast(message) {
    const toast = document.createElement('div');
    toast.className = 'fixed bottom-4 left-1/2 transform -translate-x-1/2 bg-green-500 text-white px-6 py-3 rounded-lg shadow-xl flex items-center animate-fade-in z-50';
    toast.innerHTML = `
        <div class="flex items-center">
            <i data-feather="check-circle" class="mr-2"></i>
            <span>${message}</span>
        </div>
        <div class="absolute bottom-0 left-0 h-1 bg-green-300 rounded-b-lg w-full origin-left animate-progress"></div>
    `;
    document.body.appendChild(toast);
    feather.replace();
    
    setTimeout(() => {
        toast.classList.add('opacity-0', 'transition-opacity', 'duration-300');
        setTimeout(() => toast.remove(), 300);
    }, 3000);
}

// Photo upload functionality
function setupPhotoUpload() {
    const uploadElements = document.querySelectorAll('.photo-upload');
    uploadElements.forEach(upload => {
        const input = upload.querySelector('input[type="file"]');
        const preview = upload.querySelector('.photo-preview');
        
        if (input && preview) {
            input.addEventListener('change', (e) => {
                const file = e.target.files[0];
                if (file) {
                    const reader = new FileReader();
                    reader.onload = (event) => {
                        preview.src = event.target.result;
                        preview.style.display = 'block';
                    };
                    reader.readAsDataURL(file);
                }
            });
        }
    });
}

// Helper functions for study assistance
function provideHint(questionElement) {
    // This would be connected to your question system
    const hint = questionElement.dataset.hint || "Try breaking the problem down into smaller steps.";
    
    // Show hint
    showSuccessToast(`Hint: ${hint}`);
    
    // Speak the hint using Web Speech API
    speakText(hint);
    
    // Provide similar example
    const example = questionElement.dataset.example || "Here's a similar problem: " + 
        questionElement.textContent.replace(/\d+/g, function(match) {
            return Math.floor(Math.random() * 10) + 1;
        });
    
    setTimeout(() => {
        showSuccessToast(`Example: ${example}`);
        speakText(example);
    }, 2000);
}
// AI Quiz Generation Service using Open Trivia DB API
async function generateQuizQuestions(subject, difficulty = 'medium', topic = '') {
    // Map our subject categories to Open Trivia categories
    const categoryMap = {
        'math': 19,        // Mathematics
        'science': 17,     // Science & Nature
        'history': 23,     // History
        'languages': 20,   // Mythology (as a placeholder)
        'computer_science': 18  // Computers
    };
    
    const categoryId = categoryMap[subject] || 9; // General Knowledge as fallback
    
    try {
        // Fetch questions from Open Trivia DB API
        const response = await fetch(`https://opentdb.com/api.php?amount=5&category=${categoryId}&difficulty=${difficulty}&type=multiple&encode=url3986`);
        const data = await response.json();
        
        if (data.response_code !== 0 || !data.results) {
            throw new Error('Failed to fetch questions from API');
        }
        
        // Process the API response into our question format
        return data.results.map(q => {
            // Decode URL-encoded strings and fix HTML entities
            const decodedQuestion = decodeURIComponent(q.question)
                .replace(/&quot;/g, '"')
                .replace(/&amp;/g, '&')
                .replace(/&#039;/g, "'");
            
            const decodedCorrect = decodeURIComponent(q.correct_answer)
                .replace(/&quot;/g, '"')
                .replace(/&amp;/g, '&')
                .replace(/&#039;/g, "'");
                
            const decodedIncorrect = q.incorrect_answers.map(ans => 
                decodeURIComponent(ans)
                .replace(/&quot;/g, '"')
                .replace(/&amp;/g, '&')
                .replace(/&#039;/g, "'")
            );
            
            // Combine and shuffle options
            const allOptions = [...decodedIncorrect, decodedCorrect];
            const shuffledOptions = shuffleArray(allOptions);
            
            return {
                question: decodedQuestion,
                options: shuffledOptions,
                correctIndex: shuffledOptions.indexOf(decodedCorrect),
                hint: `Think about ${q.category.toLowerCase()} concepts`,
                example: `This is a ${difficulty} level question about ${q.category.toLowerCase()}`
            };
        });
    } catch (error) {
        console.error('Error fetching quiz questions:', error);
        showErrorToast('Failed to fetch questions. Using sample questions instead.');
        return generateFallbackQuestions(subject, difficulty, topic);
    }
}

function generateFallbackQuestions(subject, difficulty, topic) {
    // Fallback questions if API fails
    const fallbackQuestions = [
        {
            question: `What is the capital of France? (Fallback for ${subject})`,
            options: ["London", "Paris", "Berlin", "Madrid"],
            correctIndex: 1,
            hint: "It's known as the City of Light",
            example: "Other European capitals include Rome and Berlin"
        },
        {
            question: `What is 5 × 7? (Fallback for ${subject})`,
            options: ["25", "30", "35", "40"],
            correctIndex: 2,
            hint: "It's 5 less than 40",
            example: "Similar to 6 × 6 = 36"
        },
        {
            question: `What is the chemical symbol for oxygen? (Fallback for ${subject})`,
            options: ["O", "Ox", "Og", "On"],
            correctIndex: 0,
            hint: "It's a single letter",
            example: "H is for Hydrogen"
        }
    ];
    
    return fallbackQuestions;
}

// Helper function to shuffle array
function shuffleArray(array) {
    for (let i = array.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [array[i], array[j]] = [array[j], array[i]];
    }
    return array;
}
function speakText(text) {
    if ('speechSynthesis' in window) {
        const utterance = new SpeechSynthesisUtterance(text);
        utterance.voice = speechSynthesis.getVoices().find(voice => 
            voice.name.includes('Female') || voice.lang.includes('en-US')
        );
        utterance.rate = 0.9;
        utterance.pitch = 1.2;
        speechSynthesis.speak(utterance);
    }
}
function setupHelpButtons() {
    // Add help button to question pages
    if (document.querySelector('.question-container')) {
        const helpBtn = document.createElement('button');
        helpBtn.className = 'help-btn';
        helpBtn.innerHTML = '<i data-feather="help-circle"></i>';
        helpBtn.onclick = () => {
            const currentQuestion = document.querySelector('.question-container:not([style*="display: none"])');
            if (currentQuestion) {
                provideHint(currentQuestion);
            }
        };
        document.body.appendChild(helpBtn);
        feather.replace();
    }
}

// Initialize all helper features
document.addEventListener('DOMContentLoaded', () => {
    setupPhotoUpload();
    setupHelpButtons();
    
    // Load voices for speech synthesis
    if ('speechSynthesis' in window) {
        speechSynthesis.onvoiceschanged = () => {
            // Voices are now loaded
        };
    }
});